drm/amdgpu: XGMI pstate switch initial support

Driver vote low to high pstate switch whenever there is an outstanding
XGMI mapping request. Driver vote high to low pstate when all the
outstanding XGMI mapping is terminated.

Signed-off-by: shaoyunl <[e-mail]>
Reviewed-by: Christian König <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

···
 	r = amdgpu_device_enable_mgpu_fan_boost();
 	if (r)
 		DRM_ERROR("enable mgpu fan boost failed (%d).\n", r);
+
+	/*set to low pstate by default */
+	amdgpu_xgmi_set_pstate(adev, 0);
+
 }
 
 static void amdgpu_device_delay_enable_gfx_off(struct work_struct *work)

drivers/gpu/drm/amd/amdgpu/amdgpu_object.h

···
 
 	/* If the mappings are cleared or filled */
 	bool				cleared;
+
+	bool				is_xgmi;
 };
 
 struct amdgpu_bo {

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

···
 #include "amdgpu_trace.h"
 #include "amdgpu_amdkfd.h"
 #include "amdgpu_gmc.h"
+#include "amdgpu_xgmi.h"
 
 /**
  * DOC: GPUVM
···
 	INIT_LIST_HEAD(&bo_va->valids);
 	INIT_LIST_HEAD(&bo_va->invalids);
 
+	if (bo && amdgpu_xgmi_same_hive(adev, amdgpu_ttm_adev(bo->tbo.bdev))) {
+		bo_va->is_xgmi = true;
+		mutex_lock(&adev->vm_manager.lock_pstate);
+		/* Power up XGMI if it can be potentially used */
+		if (++adev->vm_manager.xgmi_map_counter == 1)
+			amdgpu_xgmi_set_pstate(adev, 1);
+		mutex_unlock(&adev->vm_manager.lock_pstate);
+	}
+
 	return bo_va;
 }
 
···
 	}
 
 	dma_fence_put(bo_va->last_pt_update);
+
+	if (bo && bo_va->is_xgmi) {
+		mutex_lock(&adev->vm_manager.lock_pstate);
+		if (--adev->vm_manager.xgmi_map_counter == 0)
+			amdgpu_xgmi_set_pstate(adev, 0);
+		mutex_unlock(&adev->vm_manager.lock_pstate);
+	}
+
 	kfree(bo_va);
 }
 
···
 
 	idr_init(&adev->vm_manager.pasid_idr);
 	spin_lock_init(&adev->vm_manager.pasid_lock);
+
+	adev->vm_manager.xgmi_map_counter = 0;
+	mutex_init(&adev->vm_manager.lock_pstate);
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h

···
 	 */
 	struct idr				pasid_idr;
 	spinlock_t				pasid_lock;
+
+	/* counter of mapped memory through xgmi */
+	uint32_t				xgmi_map_counter;
+	struct mutex				lock_pstate;
 };
 
 #define amdgpu_vm_copy_pte(adev, ib, pe, src, count) ((adev)->vm_manager.vm_pte_funcs->copy_pte((ib), (pe), (src), (count)))

drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c

···
 
 	if (lock)
 		mutex_lock(&tmp->hive_lock);
-
+	tmp->pstate = -1;
 	mutex_unlock(&xgmi_mutex);
 
 	return tmp;
+}
+
+int amdgpu_xgmi_set_pstate(struct amdgpu_device *adev, int pstate)
+{
+	int ret = 0;
+	struct amdgpu_hive_info *hive = amdgpu_get_xgmi_hive(adev, 0);
+
+	if (!hive)
+		return 0;
+
+	if (hive->pstate == pstate)
+		return 0;
+	/* Todo : sent the message to SMU for pstate change */
+	return ret;
 }
 
 int amdgpu_xgmi_update_topology(struct amdgpu_hive_info *hive, struct amdgpu_device *adev)

drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h

···
 	struct kobject *kobj;
 	struct device_attribute dev_attr;
 	struct amdgpu_device *adev;
+	int pstate; /*0 -- low , 1 -- high , -1 unknown*/
 };
 
 struct amdgpu_hive_info *amdgpu_get_xgmi_hive(struct amdgpu_device *adev, int lock);
 int amdgpu_xgmi_update_topology(struct amdgpu_hive_info *hive, struct amdgpu_device *adev);
 int amdgpu_xgmi_add_device(struct amdgpu_device *adev);
 void amdgpu_xgmi_remove_device(struct amdgpu_device *adev);
+int amdgpu_xgmi_set_pstate(struct amdgpu_device *adev, int pstate);
+
+static inline bool amdgpu_xgmi_same_hive(struct amdgpu_device *adev,
+		struct amdgpu_device *bo_adev)
+{
+	return (adev != bo_adev &&
+		adev->gmc.xgmi.hive_id &&
+		adev->gmc.xgmi.hive_id == bo_adev->gmc.xgmi.hive_id);
+}
 
 #endif